Field Intensity inside Microwave Oven

[funnygirl]

Hi,

Is there any method to measure the Electromagnetic field intensity inside Microwave oven? Is there any material so that i can get information?

 

[Higgler]

Depends on the needed accuracy.
To see what's hotter/colder visually, I've used an army of marshmallows. (non technical, but visual). Moisten them a bit will make them expand faster. Marshmallows are a bit dry, but do "inflate" with RF heating.

Helps to have some chocolate and graham crackers ready after the test.

If you have to be really technical about it, that's alot more effort physically. Measuring a field disturbs it.

Nowadays, Ansoft HFSS and CST software can provide accurate field intensities via computer.

 

[biff44]

I know 2 ways that work:

paste thermal printer paper, using elmers glue, onto a piece of cardboard. Run the oven for 20 seconds or so. The elmers glue will heat up and turn the thermal printer brown where the hot spots are.

Another way is to get a sample of water in a plastic small vial, and insert a fiberoptic temperature probe into the water. Put it on the end of a plastic wand, and move the probe around thru a small sidewall hole in the oven.

Another method I have heard of but not successfuly tried is to get a bank of low voltage neon light bulbs. Just clip off any protruding wires, and Stick the bulbs in an array into something like styrofoam or dry light density wood, 15 x 15 on 1" spacing, and put in various places in oven. You will have to have a see-thru door to view which bulbs are lighting up.

http://www.MaguffinMicrowave.com

Maguffin Microwave wireless design consulting

 

[biff44]

btw, Lumasence makes the fiberoptic temperature probes. They are relatively immune from RF fields.

http://www.MaguffinMicrowave.com

Maguffin Microwave wireless design consulting